Remnant cholesterol (also referred to as remnant lipoprotein) is a category of cholesterol that comprises non-HDL and non-LDL cholesterol. Remnant lipoproteins are products of VLDL lipolysis, and include VLDL3 and intermediate-density lipoproteins (IDL, the direct precursor to LDL formation). Serum remnant cholesterol level has been identified as a predictive risk factor for coronary artery disease. In addition to remnant cholesterol, there are several subfractions of low density lipoprotein cholesterol (LDL-C) that may have relevance with regard to cardiovascular health. In particular, LDL-C is composed of a continuum of LDL particles of different densities and states of lipidation. Therapeutic reduction of serum remnant cholesterol and other lipoprotein subfraction levels may be a means for treating or reducing the risk of cardiovascular disorders.
PCSK9 is a proprotein convertase belonging to the proteinase K subfamily of the secretory subtilase family. The use of PCSK9 inhibitors (anti-PCSK9 antibodies) to reduce serum total cholesterol, LDL cholesterol and serum triglycerides is described in U.S. Pat. Nos. 8,062,640, 8,357,371, and US Patent Application Publication No. 2013/0064834.